We propose to purchase a 400 MHz Fourier-transform nuclear magnetic resonance spectrometer for multinuclear applications. Principally the instrument will be available on a continuous basis for the accumulation of 1H, 13C, 31P and 15N spectra and thereby for the characterization of organic and bioorganic molecules. The proposed instrument will be available 24 hours a day and will be graduate student and postdoctoral assistant operated. We shall initiate a program of personnel training to maximize the use of the instrument's full capabilities. The instrument will provide considerably better spectral separations and sensitivities than our current available facilities. The primary user group is carrying out research on studies of the binuclear oxygen carrier hemerythrin, photosynthesis and electron transport, mechanisms of enzyme inhibition and the design of anticonvulsant, antidepressant and anticoagulant drugs, the mode of action of proteases, and the total synthesis of natural products, including ophiobolin C and polynucleotides.